The decriminalisation of some drugs appeared a more realistic prospect tonight after charities backed Nick Clegg???s call for a Royal Commission to review Britain???s 40-year-old laws on illegal substances.

The Deputy Prime Minister warned that the country was losing the war on drugs today and claimed the Government had missed an opportunity by not ordering a fresh look at the legislation. His comments were immediately rejected by David Cameron, who made it clear the Coalition would not be changing policy on drugs.

But Danny Kushlick, of the Transform Drug Policy Foundation, said: ???Nick Clegg???s call is a sign the world has moved on.???

He said attitudes to drugs controls were rapidly changing around the world and accused Tory and Labour leaders of lagging behind public opinion on the issue.

Mr Kushlick said: ???The time has come for David Cameron and Ed Miliband to call a truce, end the political posturing and engage in a serious exploration of all alternatives including legal regulation. Anything less would be outdated and irresponsible.???

The Deputy Prime Minister???s comments were a response to a report by the Commons Home Affairs Select Committee this week, which urged ministers to set up a Royal Commission to examine whether the current system of drugs controls was effective.

Mr Clegg said: ???If you were waging any other war where you have 2,000 fatalities a year, your enemies are making billions in profit, constantly throwing new weapons at you and targeting more young people, you???d have to say you are losing and it???s time to do something different. I???m anti-drugs ??? it???s for that reason I???m pro-reform.???

He is praised for his leadership in facing up to a taboo subject in an article in today???s Independent by Sir Richard Branson, the Virgin Group founder, and Mike Trace, the chairman of the International Drug Policy Consortium.

They say: ???A Royal Commission may or may not be the best way to organise a review but, whatever the process, let???s stop pretending that a 50-year-old strategy, and a 40-year-old law, are sufficient to manage a 21st-century drug market.???

The charity DrugScope welcomed ???any moves towards having a mature public debate about drugs in the UK???. It said it supported creating a Royal Commission.